Flood Forecasting

Current Flood Status:

Water Safety Statement (Continues)August 8, 2017 (3:00 PM)

The Raisin Region Conservation Authority is continuing the water safety statement for the St. Lawrence River. The International Lake Ontario – St. Lawrence River Board has reduced the outlfow (through the dam) from 10,400 m³/s to 9,910 m³/s to mitigate high velocities upstream of the dam.

A Water Saftey Statement indicates high flows or other factors that could be dangerous for recreational users. Flooding is not expected.

The Raisin Region Conservation Authority is issuing a water safety statement for the St. Lawrence River. The International Lake Ontario – St. Lawrence River Board has increased the flow in the St. Lawrence River to 10,400 m³/s as a measure to reduce the water levels on Lake Ontario.

From the International Joint Commission:

“Since maintaining a continuous outflow of 10,400 m3/s is historically unprecedented, the Board along with the operators of the Moses-Saunders dam and navigation agencies will assess the safety of conditions before committing to sustaining this outflow for a longer duration. In particular, because the increased outflows will raise current velocities in the St. Lawrence River, the St. Lawrence Seaway has deployed significant additional mitigation measures to maintain safe conditions and ensure commercial navigation can continue during this period of exceptionally high flows.”

From the St. Lawrence Seaway Management Corporation:

“Pleasure craft operators are advised that this will create velocities higher than normal in the navigation channels and variations in the normal current patterns may occur. Extreme caution is requested during this period. Pleasure craft will be advised, through a bulletin, when the above situation will return to normal.”

Please note flooding is not expected along the St. Lawrence River from South Stormont through Cornwall and and South Glengarry. A water safety statement indicates high flows, unsafe banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc.

*** As a point of reference the flow this time last year was 7,600 m³/s.

Return to Normal
May 11, 2017 (2:00:00 PM)

Watershed conditions have returned to normal within the Raisin Region Conservation Authority jurisdiction. We are not anticipating any significant rise in water levels due to the current precipitation forecast. Water levels along the St. Lawrence River from South Stormont through to the Quebec border are not expected to see significant changes due to operations at the Moses-Saunders Dam to reduce water levels on Lake Ontario.

Water Safety Statement May 8, 2017 (9:00:00 AM)

The Raisin Region Conservation Authority is downgrading the weekend's Flood Watch to a Water Safety Statement. A water safety statement indicates high flows, unsafe banks, or other factors could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc. Flooding is not expected.

Flows in the region's rivers peaked in the early hours of Sunday. The rivers were contained within their banks for the most part. In some low-lying spots, the rivers overflowed into flood-plain areas. There is no sifgnificant precipitation in the forecast, and water levels are expected to gradually recede to normal levels.

The RRCA is continuing to monitor the weather and water levels throughout the region and will update this site as necessary.

Flood Watch May 5, 2017 (9:00:00 AM)

The Raisin Region Conservation Authority is issuing a Flood Watch for certain areas within the RRCA jurisdiction. Water levels in drains, creeks and rivers are currently high from the precipitation early in the week. We are anticipating another 44 mm of rain over the next 48 hours. This may cause flooding in flood-prone areas along the Raisin River near St. Andrews West, Martintown, Williamstown and Lancaster. The water levels in the lakes in North Glengarry will rise, but are being actively managed. We are expecting continued high outflows from Mill Pond over the next few days.

Peak flows in our region usually occur 12-24 hours after the rain. We are expecting rivers to peak around noon on Sunday.

The RRCA would also like to advise residents that stormwater management infrastructure such as ditches, drains, parking lots and stormwater ponds will be retaining significant amounts of water (which is completely normal). These facilities are designed to hold stormwater surges and release it slowly to the natural water courses. These areas are not intended for recreation as water that is collected may be deceivingly deep.

The RRCA is continuing to monitor the weather and water levels throughout the region and will update this site as necessary.

Water Safety Statement
May 3, 2017

The Raisin Region Conservation Authority is issuing a Water Safety Statement. Recent heavy rains have caused water levels in drains, creeks and rivers to rise. Residents should also be aware that stormwater management infrastructure such as swales, ditches, and retention ponds throughout the region may be retaining a lot of water. A water safety statement indicates high flows, unsafe banks, or other factors could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc. Flooding is not expected.

The RRCA is continuing to monitor the weather and water levels throughout the region and will update this site as necessary.

Return to Normal
April 18, 2017 - 12:00 PM

Water levels throughout the region have dropped considerably since peaking 10 days ago. Flows are within the normal range for this time year and trending downwards; flooding is not expected.

Water Safety StatementApril 11, 2017 - 4:00 PM

The Raisin Region Conservation Authority is downgrading the Flood Warning to a Water Safety Statement. Water levels in the region's drains, creeks and rivers have receded significantly since peaking in the early hours of April 8. Water levels in the lakes in North Glengarry have also come back down into the normal operating range. Although there is still precipitation forecast over the next few days, the chance of flooding has be greatly reduced.

A water safety statement indicates high flows, unsafe banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc.

The RRCA will continue to monitor water levels throughout the region, and post updates as required.

Flood Warning -Update
April 8, 2017 - 7:00 PM

Water levels in the region's creeks and rivers peaked last night, and are now receding. Several roadways around the region still remain flooded. Motorists should respect road closures where posted. There is a chance of more rain in the 5-day forecast which could raise water levels again. The RRCA continues to monitor the situation and will post updates.

The Raisin Region Conservation Authority is upgrading the Water Safety Statement to a Flood Outlook Statement. With recent snow melt and precipitation, water levels are at bank-full condition throughout the watershed.

The additional precipitation forecast over the next 24 hours may cause some flooding in flood-prone areas. These areas may include - Northern branches of Raisin River (upstream and including St. Andrews West); main branch of the Raisin River (downstream of Martintown, including McGillivary Road); main branch of the Raisin River (south of Williamstown, including Loyalist Road); south branch of the Raisin River near Cornwall Centre Road; south branch of the Raisin River near Kinloch Road and Cashion Road. Water levels in the lakes in North Glengarry (Loch Garry, Middle Lake and Mill Pond) are high. Low-lying areas downstream of Mill Pond along the Garry River to Deslile are expected to experience nuisance flooding as the water levels in the lakes are managed.

The RRCA will continue to monitor the situation and post updates on this website and social media as conditions evolve.

Water Safety Statement
April 3, 2017

The Raisin Region Conservation Authority is advising caution near local rivers and creeks. Water levels are currently rising and water is moving quickly.

Long range forecasts are showing an accumulated precipitation total of 70mm or more over the next 5 days. Upper portions of the watershed still have significant snowpack. Combined runoff from the rainfall and snowmelt may cause ponding and potential for flooding in low lying areas.

Water is currently contained within the river banks for the most part, and wide-scale flooding is not expected.

The RRCA will continue to monitor the situation and post updates on this website and social media as conditions evolve.

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The Raisin Region Conservation Authority monitors water levels throughout Cornwall; South Glengarry; and large portions of North Glengarry and South Stormont.

Return to Normal
March 7, 2017

Water levels in the region have dropped considerably over the past couple of days. Flooding is not expected in the near future. We continue to advise caution near creeks and rivers where stream flow may increase with rainfall plus snow melt.

Water Safety Statement
Feb 28, 2017

The Raisin Region Conservation Authority is advising caution near local rivers and creeks. Water levels are currently high, and water is moving quickly. Water is contained within the river banks for the most part, and flooding is not expect. There may be areas of ponding or nuisance flooding in low-lying areas.

Environment Canada has issued the following special weather statement for our area.

Rain is expected to spread across southern Ontario from west to east tonight and taper off on Wednesday. Although rainfall amounts are not expected to be overly significant, the ground has a reduced ability to absorb further rainfall due to recent rains and snowmelt. General rainfall amounts of 15 to 25 millimetres are likely, though isolated spots may see higher amounts, especially in areas that receive thunderstorms. Caution is advised near creeks and rivers where stream flow is expected to increase. Ponding of water may occur in some areas as well.

A water safety statement indicates high flows, unsafe banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc.

The RRCA will continue to monitor water levels throughout the region, and post updates as required.

Flood Forecasting and Warning in the RRCA

The Ontario Ministry of Natural Resources and Forestry (MNRF) is responsible for flood related emergencies.

Flood forecasting and warning has been delegated to Conservation Authorities.
If a local emergency is declared, MNRF will work directly with the municipality and in consultation with the Conservation Authority.

The Raisin Region Conservation Authority monitors water levels throughout Cornwall; South Glengarry; and large portions of North Glengarry and South Stormont.

About Flood Forcasting Notices

Depending on watershed conditions, the flood status will be one of the following:

Normal
No flood conditions exist.

Watershed Conditions Statement - Water Safety
High flows, unsafe banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc. Flooding is not expected

Watershed Conditions Statement - Flood Outlook
Early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high wind or other conditions that could lead to high runoff, cause ice jams, lakeshore flooding or erosion.